Numerical analysis of the tympanic membrane vibrations

The intact tympanic membrane ensures a good hearing quality for humans. Sometimes, the tympanic membrane is perforated and because of that the hearing suffers. The tympanic membrane is reconstructed by covering the perforation with autogenous tissues that changes the tympanic membrane geometry, and the hearing is restored. During the hearing restoration operation, the surgeon influences the thickness of the tympanic membrane and the fixation type. Nevertheless, it is still not clear why in some cases the hearing is deeply affected by small perforation. For this reason, a numerical model has been constructed for the intact and perforated tympanic membrane with common 6mm(2) perforation. The numerical analysis of vibrations was performed in 500, 1000, 1500, 2000 Hz frequencies with the intensity of 45 dB aiming to investigate how the healthy and perforated tympanic membranes move. The acquired data at 1000 Hz correspond to the literature data. Numerical analysis shows that the maximum amplitude in intact and perforated tympanic membranes differs 2 times in 1500 Hz, 70 times in 2000 Hz, while in 500 and 1000 Hz they move similarly. The analysis on how the tympanic membrane fixation place affects its movements after the myringoplasty and according to the geometry of the tympanic membrane was also performed.